1. Field of the Invention
The present invention generally relates to a metal/ceramic bonding article having a ceramic substrate and a metal plate bonded to the ceramic substrate, and a method for producing the same. More specifically, the invention relates to a metal/ceramic bonding article wherein a metal plate of a Cuxe2x80x94Ni or Cuxe2x80x94Mnxe2x80x94Ni alloy serving as a resistive element is bonded to a ceramic substrate and which is used for an electronic member for resistance, such as a shunt resistive element, and a method for producing the same.
2. Description of the Prior Art
In conventional electronic members for resistance, such as shunt resistive elements, an alloy plate serving as a sheet resistor precisely worked by a press working or the like is bonded to a ceramic substrate via a brazing filler metal, such as an Ag brazing filler, by means of the brazing and soldering (see Japanese Patent Laid-Open No. 11-97203).
However, in such an electronic member bonded via a brazing filler metal, a worked sheet resistor must be arranged on a ceramic substrate at a precise position to be bonded thereto. In particular, when a very small resistor having a size of 10 mmxe2x96xa1, such as a hunt resistive element, is bonded toga ceramic substrate, the displacement of the resistor is easy to occur, and it is difficult to bond one or a plurality of resistors to one ceramic substrate, so that there is a problem in that the displacement failure of the resistor is not only caused, but productivity also considerably deteriorates.
In addition, since the alloy plate serving as the resistor has a low solder wettability, there is a problem in that there are some cases where bonding failure may occur when a semiconductor device or the like is mounted on the alloy plate.
It is therefore an object of the present invention to eliminate the aforementioned problems and to provide a metal/ceramic bonding article capable of reducing the displacement failure of parts to improve productivity, and a method for producing the same.
It is another object of the present invention to provide a metal/ceramic bonding article capable of preventing bonding failure when a semiconductor device or the like is mounted thereon.
In order to accomplish the aforementioned and other objects, the inventors have diligently studied and found that it is possible to reduce the displacement failure of a pattern to improve productivity by bonding a metal plate of an alloy containing copper and nickel to a ceramic substrate, applying a resist on a predetermined portion of the metal plate, removing an undesired portion of the metal plate by etching, and removing the resist to form a pattern having a predetermined shape. As a result, the inventors have made the present invention.
According to one aspect of the present invention, there is provided a method for producing a metal/ceramic bonding article, the method comprising the steps of: bonding a metal plate of an alloy containing copper and nickel directly to at least one side of a ceramic substrate; applying a resist on a predetermined portion of the metal plate to remove an undesired portion of the metal plate by etching; and removing the resist to form a pattern having a predetermined shape of the alloy on the ceramic substrate.
In this metal/ceramic bonding article producing method, the alloy preferably contains manganese. The metal plate is preferably made of an electric resistance material. The etching is preferably carried out by using an etchant containing copper chloride or iron chloride. In addition, a plating is preferably carried out on the entire surface or part of the metal plate. The plating is preferably Ni plating, Ni alloy plating or Au plating.
According to another aspect of the present invention, a metal/ceramic bonding article comprises: a ceramic substrate; and a metal plate bonded directly to at least one side of the ceramic substrate, the metal plate being made of an alloy containing copper and nickel, and the metal plate being formed so as to have a pattern having a predetermined shape.
In this metal/ceramic bonding article, the alloy preferably contains manganese. The metal plate preferably has a peel strength of 10 N/cm or more. The metal/ceramic bonding article preferably has an insulation resistance of higher than 1000 Mxcexa9. In addition, a plating is preferably carried out on the entire surface or part of the metal plate. The plating is preferably Ni plating, Ni alloy plating or Au plating.
According to a further aspect of the present invention, there is provided an electronic member for resistance, which comprises anyone of the above described metal/ceramic bonding articles.
According to a still further aspect of the present invention, there is provided a module assembled by using any one of the above described metal/ceramic bonding articles.